See text Pipistrellus is a genus of bats in the family Vespertilionidae and subfamily Vespertilioninae.

The size of the genus has been considerably reduced as a result of work during the 1990s and 2000s, with genera such as Arielulus, Hypsugo, Falsistrellus, Neoromicia, Parastrellus, Perimyotis, Scotozous, and Vespadelus being split off.

Several other genera in the subfamily Vespertilioninae have also been merged with Pipistrellus in previous classifications.

Species of the Southern Hemisphere separated to genus Falsistrellus are sometimes referred to as false pipistrelle or falsistrelle.

[2] They are somewhat distinguished from their much larger relatives, the noctule bats Nyctalus by their weak, fluttery flight reminiscent of a butterfly, though a few species are more direct in their flight.